Long-term results from modified sphincteroplasty in patients with traumatic sphincter injury: a retrospective study

ABSTRACT BACKGROUND: The results from sphincteroplasty may worsen over time. Reseparation of the rectum and vagina/scrotum in conjunction with sphincteroplasty achieves good results. Improving the surgical effect of sphincteroplasty through perineal body reconstruction is crucial. OBJECTIVE: To evaluate the long-term results from anterior sphincteroplasty and perineal body reconstruction (modified sphincteroplasty) among patients with traumatic sphincter injury. DESIGN AND SETTING: Retrospective study among patients who underwent modified sphincteroplasty in a university hospital between January 2006 and December 2018. Fifty patients were evaluated in detail. METHODS: The following variables were evaluated: gender, age, additional disease status, time interval between trauma and surgery, surgical technique, duration of hospitalization, follow-up period after surgery, manometric values, electromyography results, magnetic resonance imaging scans, Wexner scores, satisfaction levels with surgery and surgical outcomes. RESULTS: The patients’ mean age was 44.6 ± 15.1 years. The median follow-up period was 62 months (range, 12-118). The mean Wexner scores preoperatively, postoperatively in first month (M1S) and at the time of this report (AAS) were 15.5 ± 3.2, 1.9 ± 3.15 and 3.9 ± 5.3, respectively. Although improvements in the patients’ mean Wexner scores became impaired over time, the postoperative Wexner scores were still significantly better than the preoperative Wexner scores (P = 0.001). CONCLUSION: Good or excellent results were obtained surgically among patients with traumatic sphincter injury. Performing perineal body reconstruction in addition to sphincteroplasty can provide better long-term continence. Surgical outcomes were found to be better, especially among patients younger than 50 years of age and among patients who underwent surgery within the first five years after trauma.

sphincteroplasty. 4,5,9,12,18 Reseparation of the rectum and the vagina/ scrotum in conjunction with sphincteroplasty achieves good results, and performing perineal body reconstruction in addition to sphincteroplasty can provide better long-term continence. 19

OBJECTIVE
In this study, we aimed to evaluate the long-term results from anterior sphincteroplasty and perineal body reconstruction (modified sphincteroplasty) among patients with traumatic sphincter injuries.

METHODS
This study was approved by our university's local ethics committee (number: 2018/203). Seventy-four surgical patients with AI who were seen between January 2006 and December 2018 were evaluated retrospectively. Patients older than 65 years of age with poor health status (n = 4), patients with past surgical history due to AI (n = 2), patients with multiple sphincter injuries (n = 3), patients with inflammatory bowel disease (n = 3), patients with neurological disease (n = 7), patients with diabetes mellitus (n = 2) and patients with lack of data (n = 7) were excluded from the study. A total of 50 patients who underwent modified sphincteroplasty were evaluated in detail.
The sphincter defect was evaluated preoperatively by means of pelvic magnetic resonance imaging (MRI), in all patients. Early reconstruction was defined as 'surgery performed within 14 days after the trauma' . A preoperative evaluation using anal manometry and anal electromyography (EMG) was performed in the cases of patients without early reconstruction. Patients with AI following vaginal delivery had grade 3 injuries (involving partial or complete disruption of the anal sphincter complex, i.e. including the external anal sphincter and the internal anal sphincter) and grade 4 injuries (involving disruption of the anal mucosa in addition to the sphincter complex). 20 The patients' AI scores were evaluated using the Cleveland Clinic Florida Incontinence Scoring Scale (Wexner score) preoperatively, postoperatively in the first month (M1S) and at the time of this report (AAS). The assessment comprised five items: frequency of AI (for solid, liquid and gas components), wearing of pads and lifestyle alteration due to AI. 21 The total score (range: 0-20) was calculated by summing the '0-4' points for each parameter (0 points for complete continence and 20 points for complete incontinence, according to the Wexner score).
In addition, the patients' satisfaction was evaluated using the Cleveland Clinical Quality of Life Score, on a scale of 1-10 points (1 point, 'lowest' satisfaction score of patient; 10 points, 'highest' satisfaction score relating to surgery).
The outcome was classified as excellent (full continence), good (incontinence in relation to flatus or sporadic loss of liquid stool was encountered postoperatively, after less than one month); moderate (incontinence was regularly experienced in relation to liquid/ solid stools, but incontinence episodes were reduced by 50% or more postoperatively); or poor (persistent AI with less than 50% reduction of incontinence episodes postoperatively). 15 All the data were obtained using medical record and interviews.

Intervention techniques
Bowel preparation and urinary drainage with a catheter were not routinely performed. Antibiotic prophylaxis was administered, consisting of 1 g of cefazolin and 500 mg of metronidazole. The operations were performed in the lithotomy position by the same surgical team (TC, MOT). The final aim of the surgery was to perform reconstruction of the pelvic floor for continence (Figure 1).

Anterior sphincteroplasty was performed under direct vision.
A curvilinear incision was made in the perianal area and the dissection was completed with preservation of the rectal wall. Both sides of the puborectalis muscles were dissected until the mesorectum tissue appeared. We attempted to preserve the pudendal nerves by avoiding excessive dissection laterally. Subsequently, bulbospongiosus muscles were introduced and the tissue layers (puborectalis muscles, external sphincter muscles, internal anal sphincter muscles and mucosa) were sutured at the midline, from deep to superficial, using 2-0 delayed absorbable polyglactin suture material (Vicryl, Ethicon Inc, NJ, United States) (Figure 2).
The external anal sphincters were mainly reconstructed using an overlapping technique (Figure 3). In most cases, overlapping sphincter reconstruction was performed by attempting to preserve muscle mass without removing the fibrotic area at the median line. Lastly, the bulbospongiosus muscles were reconstructed, and the posterior part of the bulbospongiosus muscles, median edge of the transverse perineal muscles, anterior part of the puborectalis muscles and anterior part of the external anal sphincter muscles were combined in the anterior part to reconstruct the perineal body (Figure 4). We aimed to create a circular muscle mass around the anal canal. Surgical drains were not used routinely ( Figure 5). According to the status of the perineal injury, a temporary stoma was provided for fecal diversion.
The patients were discharged from the hospital after bowel movements had become reestablished. They were evaluated postoperatively after the first week, first month, third month, sixth month, first year and at the time of making the current report.

Statistical analysis
The patients were evaluated regarding gender, age, additional disease status, time interval between trauma and surgery, surgical technique, duration of hospitalization, follow-up period after surgery, manometric values, EMG results, MRI scans, Wexner scores, satisfaction levels with surgery and surgical outcomes.
Variables were presented as percentages (%), means ± standard deviations (SD) and medians (minimum-maximum). Categorical variables were evaluated using the chi-square test. Continuous variables were assessed using one-way ANOVA. Groups were

RESULTS
Out of the total of 50 patients evaluated in our study ( Table 1) The mean preoperative Wexner score was higher than the mean M1S Wexner score and mean AAS Wexner score. Although the improvement in mean Wexner score decreased over time, it was still better than the preoperative values (preoperative versus M1S, P < 0.001; preoperative versus AAS, P < 0.001; M1S versus AAS, P = 0.024).
Among the 50 patients evaluated here, 32 (64%) were younger than 50 years of age. There was a statistically significant difference in mean AAS Wexner score between the age groups (younger or older than 50 years), and improvements in mean AAS Wexner score were obtained among the patients younger than 50 years of age (P = 0.024).
Out of 36 patients who were operated within the first five years after their sphincter injury, 16 patients underwent early reconstruction. Although there was no statistically significant difference in AAS Wexner score for patients who underwent early reconstruction, statistically significant better results were obtained among the patients who underwent surgery within first five years after the trauma (P = 0.031).
Continence of gases, fluids and solids was achieved at M1S, respectively in 72% (n = 36), 86% (n = 43) and 92% (n = 46) of the patients after the modified sphincteroplasty. However, the continence rates for gases, fluids among these patients at AAS were, respectively, 64% (n = 32), 74% (n = 37) and 84% (n = 42). The postoperative improvement in continence status remained stable in 36 patients during the follow-up period, while the continence status of the other 14 patients deteriorated to varying degrees over time. Good or excellent continence was obtained in 84% of patients at AAS.
There was no statistically significant difference in AAS Wexner score or in patients' satisfaction with surgery, between the overlapping and end-to-end modified sphincteroplasty groups (P > 0.05 for both). The mean score regarding satisfaction with surgery was 8.1 ± 2.5. Although satisfaction with surgery was perfect (10 points) in 42% of the patients (n = 21), the level of satisfaction with surgery was below 5 points in 10% of the patients (n = 5). Lower AAS Wexner scores correlated with greater satisfaction with surgery.

DISCUSSION
All the patients in this study presented traumatic anal sphincter injury. Modified sphincteroplasty was performed in all cases, and the levels of satisfaction with surgery remained high over the long term. Incontinence scores were lower among patients younger than 50 years of age and among patients who underwent surgery within the first five years after the trauma.
Incontinence is a symptom of varying severity that can range from mild leakage of gas to complete loss of fecal control. It has been reported that its prevalence generally ranges from 1% to 21%, although it is seen more frequently among individuals over the age of 65 years. 2 Different incidence rates may be associated with variations in the definition of "incontinence". ' Anorectal incontinence' , ' AI' and 'fecal incontinence' may be used to describe incontinence. 2,4,[7][8][9] While uncontrolled leakage of gases and stools is defined as AI, 4 fecal incontinence usually describes leakage of stools. 8 Diarrhea, neurological diseases, surgical or obstetrical trauma and advanced age are among the causes of AI. 7 Primary incontinence may be seen as a result of congenital diseases, and secondary incontinence may be seen in acquired cases. 2 The most common etiological reason for referrals to colorectal surgeons is traumatic sphincter injury, among the many different cases. It is crucial to obtain detailed anamnesis of each case.
However, it needs to be borne in mind that some patients may tend to respond incorrectly during questioning to obtain the detailed past medical history.
During the physical examination, the perineal region and anoderm is evaluated for any tears or leakage. Detailed evaluation is crucial for differentiating leakage from AI in diseases such as rectal prolapsus. 12,[15][16][17] It is important to recognize the type, frequency and extent of AI. Scoring systems have been developed for evaluation of AI. One of the most widely used scales is the Wexner scoring system. 21 All of the patients in the present study presented acquired traumatic sphincter injuries, and the Wexner scoring systems were used for assessment of AI at different times among these patients.
Diagnostic endoanal ultrasonography (USG), anorectal manometry, pudendal nerve evaluation, EMG, defecography and colonoscopy may be performed. 2 Predictions from preoperative manometric measurements may yield conflicting outcomes. 9,18,22 In manometric measurements made in the present study, there was no significant postoperative result regarding the mean resting pressure, which was more related to internal anal sphincters.
Statistically significant results were obtained with regard to mean squeeze pressures postoperatively, which were associated with external sphincter functions and voluntary contraction.
MRI identifies the structure of the external anal sphincters and puborectalis muscles, and also the pelvic floor structure. 13  Over long-term follow-up, decreasing success rates have previously been reported. 1,17 Sphincteroplasty has been reported to yield short-term improvement (68-74%) in AI, but the success rate may decline to 0-50% over time. 1,4,12,16,24 Damage to the distal branches of the pudendal nerve during surgery, variation in surgical technique, suture breakage and muscle denervation with age are some of the possible causes of this deterioration over the long term. 16,25 Despite this deterioration of continence, patients may feel satisfied with their surgical outcomes and quality of life. 17  However younger patients (< 50 years old) had better surgical outcomes than older ones. 9,15,22 In the present study, the postoperative mean AAS Wexner score of younger patients (18-50 years old) was also significantly better than those of patients older than 50 years (P = 0.024).
Some studies have pointed out that biofeedback treatment or reoperation might be useful for preserving the good results. 16,25,26 Modified sphincteroplasty was performed on all patients in this study. Significant improvement in continence was observed in most of the patients during the long follow-up period (median of 62 months; range, 12-118 months). Similar or worse outcomes after sphincteroplasty were reported in some other studies with long follow-up periods (60 months or longer). 4,12,17,24 It was considered that the possible reasons for a successful outcome in the present study may have related to the surgical technique and the patient group selected, such as those with traumatic sphincter injury.
In the present study, overlapping sphincteroplasty was performed in the majority of cases (82%). Perineal body reconstruction was performed in all cases and lateral dissection was limited during the surgery. According to our experience, strengthening of all the available functional muscles, restoration of normal anatomy and reseparation of the rectum and vagina/scrotum in conjunction with use of modified sphincteroplasty increased the success rate. It has been emphasized that, especially in cases of high-grade obstetric injuries, reconstruction should be performed by an expert and specialist team during the early period. 20 In the present study, modified sphincteroplasty was performed always by same expert surgical team. Although better results were not obtained among patients who underwent early reconstruction (P = 0.308), patients who underwent modified sphincteroplasty within five years after the trauma had better results than did those whose surgery was performed later.
There are some limitations to our study. Firstly, this was a retrospective study, and endoanal USG and manometry data were not obtained in all cases. Secondly, the results were not compared among the etiological subgroups in detail because of the small sample size. On the other hand, the study population was homogenous and long-term follow-up was obtained.

CONCLUSION
Good or excellent results were obtained through use of modified sphincteroplasty, especially in treating traumatic sphincter injury. The surgical outcomes were found to be better among patients younger than 50 years of age and among patients who underwent surgery within the first five years after their trauma. It is crucial to recognize patients with AI and to direct them to centers with reconstruction experience, without delay. Lastly, perineal body reconstruction may provide long-term preservation of improvement when combined with anterior sphincteroplasty, among patients with traumatic AI.